(CNN) - The CDC’s new study found that between 2011 and 2015, 39 percent of women and 54 percent of men ages 15 to 44 said they had never been tested for HIV outside of donating blood.
In age group 15 to 24, there was an increase to 64 percent of women and 74 percent of men who reported never being tested.
The most common reason young adults gave for not getting tested is that, they believe they were "unlikely to have been exposed to HIV," the report states.
According to the CDC, 166,000 of the more than 1 million HIV-positive people in the United States are unaware of their status.
Forty percent of new HIV infections are transmitted by people whose HIV status remains undiagnosed.
Doctors recommend testing for anyone who has had sex.
Copyright 2018 CNN. All rights reserved.